SEX HORMONE-BINDING GLOBULIN (SHBG) - (P)
Test Code: SHBG
Test Indications: This test is used for the differential diagnosis and followup of female patients with symptoms of hyperandrogenism. It can be used to calculate the free androgen index (FAI) from the ratio of total testosterone (T) to SHBG. This estimates the approximate amount of free testosterone as there is a direct correlation between calculated FAI and free testosterone level.
Patient Preparation Instructions: Multivitamins (45–125 µg biotin) or biotin-only supplements up to 1 mg per day do not interfere with this test. Samples should not be taken from patients receiving therapy with high biotin doses (i.e. >5 mg/day) until at least 8 hours after the last dose.
Plasma: 2.0 mL
Stability 7 days refrigerated, 12 months frozen
Serum: 2.0 mL
Samples must be transferred to an aliquot tube and stored frozen if analysis will not be complete within 48 hours (#110-10-05 Serum / Plasma Separation Procedure & Transport)
Female: 16-120 nmol/L
Male: 10-73 nmol/L